The present invention relates generally to vacuum appliances.
Vacuum appliances are well known. For example, vacuum appliances that are capable of picking up both wet and dry material, commonly referred to as wet/dry vacuums or wet/dry vacs, are often used in workshops and other environments where both wet and dry debris can accumulate. Wet/dry vacuums conventionally consist of a collection canister or drum, usually mounted on a dolly having wheels or casters, and a powerhead within which a motor and impeller assembly is mounted. The motor and impeller assembly creates a suction within the drum, such that debris and/or liquid are drawn into the drum through an air inlet to which a flexible hose can be attached. A filter within the drum prevents incoming debris from escaping from the drum while allowing filtered air to escape. As debris collects on the filter, the performance of the vacuum decreases. As the filter becomes dirtier, the performance of the vacuum decreases until a point that is noticeable by the operator. It is normally at this time that the operator will clean or replace the filter.
In an effort to provide an indication to a user that the filter is clogged, some vacuum systems provide an indicator showing how clean the filter is. Some known indicators read the pressure inside the filter to make a reading as to how clean the filter is. Unfortunately, this is not a truly accurate way to determine how clean the filter is. Many factors could cause an inaccurate or false reading using this method including, a clogged hose, an accessory with a small opening, using an accessory on carpet, picking up water, etc.
The present application addresses shortcomings associated with the prior art.